Ski sharpener



FIG. 1 is a top front perspective view of the ski sharpener embodying my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a right side elevational view thereof, the left side being a mirror image;

FIG. 4 is a rear elevational view thereof. 

The ornamental design for the ski sharpener, as shown and described. 